Engineered chimeric antimicrobial agents against gram-positive bacteria

Abstract

The present invention relates to chimeric bacteriophage lysins which can be used to sanitize surfaces, for the treatment of bacterial infections and/or for the selective treatment of body odor-causing bacteria. The invention also includes synergistic combinations, methods of treatment and isolated polynucleotides which encode the chimeric lysins.

1 . A chimeric bacteriophage lysin comprising a catalytic domain of a first phage lysin and a binding domain of a second phage lysin, wherein the chimeric lysin has killing activity against a plurality of  Staphylococcus  species, wherein the lysin comprises an amino acid sequence set forth in:
 a) SEQ ID NO: 11, or a variant thereof wherein said variant is capable of killing staphylococci;   b) amino acids 1-165 and 170-338 set forth in SEQ ID NO: 9, or a variant thereof wherein said variant is capable of killing staphylococci;   c) amino acids 1-145 and 150-242 set forth in SEQ ID NO: 13, or a variant thereof wherein said variant is capable of killing staphylococci;   d) amino acids 1-165 and 170-262 set forth in SEQ ID NO: 15, or a variant thereof wherein said variant is capable of killing staphylococci.   
     
     
         2 . The chimeric lysin of  claim 1 , wherein the variant comprises a sequence having at least 85%, at least 90% or at least 95% sequence identity to the amino acid sequence set forth in a) SEQ ID NO: 11; b) SEQ ID NO: 9; c) SEQ ID NO: 13; or d) SEQ ID NO: 15. 
     
     
         3 . The chimeric lysin of  claim 1 , wherein the said first and second binding domains are fused by a linker peptide. 
     
     
         4 . The chimeric lysin of  claim 3 , wherein the linker peptide has the amino acid sequence set forth in amino acids 166-169 of SEQ ID NO: 9. 
     
     
         5 . The chimeric lysin of  claim 1 , wherein:
 a) the chimeric lysin has the amino acid sequence set forth in SEQ ID NO: 11;   b) the chimeric lysin has the amino acid sequence set forth in SEQ ID NO: 9;   c) the chimeric lysin has the amino acid sequence set forth in SEQ ID NO: 13;   d) the chimeric lysin has the amino acid sequence set forth in SEQ ID NO: 15.   
     
     
         6 . The chimeric lysin of  claim 1 , wherein:
 i) the chimeric lysin set forth in a) also has killing activity against  E. faecalis  and/or  S. hominis  and  S. epidermidis  in human sweat;   ii) the chimeric lysin set forth in b) has killing activity against  hominis  and  S. epidermidis  in human sweat;   iii) the chimeric lysin set forth in d) has killing activity against  S. epidermidis  in human sweat.   
     
     
         7 . The chimeric lysin of  claim 1 , wherein the chimeric lysin in a) has killing activity against methicillin-resistant and methicillin-sensitive strains of  S. aureus.    
     
     
         8 . The chimeric lysin of  claim 1 , wherein the chimeric lysin in a) has killing activity against Rifampicin resistant strains of  E. faecalis  and Vancomycin resistant strains of  E. faecalis.    
     
     
         9 . The chimeric lysin of  claim 1 , wherein the chimeric lysin in a) has killing activity over a pH range of about 4-10 and/or over a salt concentration of about 0-500 mM NaCl. 
     
     
         10 . An isolated polynucleotide molecule encoding a chimeric lysin of  claim 1 . 
     
     
         11 . The isolated polynucleotide molecule of  claim 10 , wherein:
 i) the nucleic acid sequence in a) has at least 85% sequence identity to SEQ ID NO: 12;   ii) the nucleic acid sequence in b) has at least 85% sequence identity to SEQ ID NO: 10;   iii) the nucleic acid sequence in c) has at least 85% sequence identity to SEQ ID NO: 14;   iv) the nucleic acid sequence in d) has at least 85% sequence identity to SEQ ID NO: 16;   due to the degeneracy of the genetic code.   
     
     
         12 . A composition comprising one or more chimeric lysins of  claim 1 . 
     
     
         13 . The composition of  claim 12 , further comprising an antibiotic and/or a native lysin such as PlyV12 (SEQ ID NO: 17) or LysEF-P10 (SEQ ID NO: 19). 
     
     
         14 . The composition of  claim 13 , wherein the chimeric lysin is LKCHAPV12 (SEQ ID NO: 9) and the native lysin is PlyV12 (SEQ ID NO: 17). 
     
     
         15 . The composition of  claim 12 , for sanitizing or decontaminating porous or non-porous surfaces. 
     
     
         16 .- 18 . (canceled) 
     
     
         19 . A method of prophylaxis or treatment of a staphylococcal infection in a mammal, comprising administering to said mammal one or more chimeric lysins of  claim 1 . 
     
     
         20 . The method of  claim 19 , wherein the staphylococcal infection causes body odor in a human and the one or more chimeric lysins are selected from  claim 1 . 
     
     
         21 . A method for decontaminating inanimate surfaces suspected of containing infectious bacteria, comprising treatment of said surfaces with a bactericidal or bacteriostatically effective amount of at least one chimeric bacteriophage lysin of  claim 1 .